Monsters are real. They may wear business suits or military uniforms, but they have walked among us. We see the evidence of their works in the bleaker chapters of human history and this week, on Holocaust Memorial Day, we marked the darkest chapter of all.

We remember the persecution and mechanised slaughter of 17 million people, more than a third Jewish. Entire communities, huge segments of entire races and any of those the Nazis found to be deviant or defective were rounded up and shipped to camps like Auschwitz and Belsen to be murdered.

This outrageous regime was only made possible with the blind capitulation of thousands of otherwise normal people. Of this, Italian writer and holocaust survivor Primo Levi said: Monsters exist, but they are too few in number to be truly dangerous. More dangerous are the common men, the functionaries ready to believe and to act without asking questions.

The Nazis were successful at mass murder because they desensitised and normalised it. They inured every level of government and military to atrocity with endless layers of bureaucracy that reduced millions of lives to lines in a ledger book, transport manifests and piles of unclaimed belongings.

Hannah Arendt described this as the banality of evil when she covered the trial of Adolf Eichmann in Jerusalem in 1961. Sitting across from this little grey man in court, the architect of the final solution, Arendt described Eichmann as being terribly and terrifyingly normal.

It is that realisation, that horrific acts can be committed by humdrum men that for me represents the most powerful warning of the Holocaust. Monsters are real and we need to keep reminding ourselves of that.

As the Holocaust begins to move out of living memory, it is incumbent on all of us to keep that memory alive and to pass it on to our children and theirs to come. Recent research shows how imperative that is. According to a poll reported by BBC News, one in 20 UK adults believe the Holocaust didnt happen, a full eighth of the population believe it has been exaggerated.

I have written before about the incident last year when I spent some time in hospital and the man in the bed opposite volunteered his belief that the Holocaust was all a hoax. In the argument that followed, he revealed that the basis for his position was rooted in videos hed seen on YouTube.

Stronger than the sword is my soul

Challenging antisemitism and Holocaust denial falls to each of us. We have seen the grim evidence of its revival in the rise of casual antisemitism in UK politics and in two mass shootings in crowded synagogues last year alone. This isnt going away. Hate still blooms against the Jewish people and many of those others persecuted by the Nazis. We must do everything we can to stamp it out.

In the study of the Holocausts gruesome history, we come to the names of its perpetrators before we come to the names of its victims and survivors. Perhaps that is because the names of those who perished are so innumerable, their stories too heartbreaking. But the preservation of their memory is the most important thing we can do.

The fact that we are here, living amongst many of the communities that the Holocaust sought to extinguish is evidence that the Nazis failed. That human spirit prevailed over evil.

I was reminded of this when, on a parliamentary visit to Strasbourg in 2017, I stopped at the Synagogue de Paix which is built on the site of the Gestapo headquarters of Western Europe. Above the front door is a legend written in French and in Hebrew: Stronger than the sword is my soul.